1. Technical Field
The present invention relates to stators for rotating electric machines that are used in, for example, motor vehicles as electric motors and electric generators.
2. Description of Related Art
Japanese Patent Application Publication No. JP2001-103697A discloses a stator for a rotating electric machine. In the stator, lead portions of phase windings of a stator coil, which are connected to ends of other phase windings of the stator coil, are fixed to a coil end part of the stator coil by an electrically-insulative adhesive instead of by binding them to the coil end part with threads. With the above method of fixing the lead portions to the coil end part, it is possible to prevent scratches from being formed on the lead portions by friction, secure electrical insulation between the phase windings of the stator coil and reduce man-hours required for manufacturing the stator.
However, with the above stator, in some cases, vibration load imposed on spots where the lead portions (or lead wires) are fixed to the coil end part of the stator coil may become large, thereby lowering the vibration resistance of the stator; those cases include cases where the stator coil is made of electric conductors having a large cross-sectional area so as to reduce the electrical resistance of the stator coil and cases where the rotating electric machine is used in a motor vehicle that is subject to severe vibration.
The above problem may be solved by increasing the amount of the adhesive used to fix the lead portions to the coil end part of the stator coil. However, in this case, the manufacturing cost of the stator would be increased with the increase in the amount of the adhesive.
Moreover, in recent years, with diversification in stator coil specifications, the arrangement of the lead portions has become complicated and thus the number of the spots where the lead portions are fixed to the coil end part of the stator coil has been increased. Consequently, the amount of the adhesive used to fix the lead portions to the coil end part of the stator coil has been accordingly increased, thereby resulting in an increase in the manufacturing cost of the stator. In addition, with the complication of the arrangement of the lead portions and the increase in the number of the spots where the lead portions are fixed to the coil end part of the stator coil, the gap between the stator coil and a frame of the rotating electric machine which receives the stator therein may be accordingly reduced, thereby lowering the environmental resistance of the rotating electric machine.